Universally adjustable and focusable alarm apparatus and electric circuitry therefor

ABSTRACT

Apparatus having a base attachable to a surface. A hollow holder is universally supported by the base and an electric element of a light beam transmitting and receiving circuit is mounted in the holder. The light beam travels through an outer end opening of the holder and fitted to the holder to extend across the outer end opening are a light focusing lens and a light filter. A rheostat is provided in the circuit to adjust the intensity of the light beam. The apparatus has an alarm circuit which is energized when the light beam is broken by an object of a predetermined size and the alarm circuit includes an audible and a visual signalling device as well as a two-way switch for selectively and alternatively controlling the two devices.

United States Patent Litman et al.

[151 3,653,021 [451 Mar. 28, 1972 [s4] UNIVERSALLY ADJUSTABLE AND1,992,199 2/1935 Fitzgerald ..340/258 B x FOCUSABLE ALARM APPARATUS AND2,099,868 11/1937 sirlilg et al.... ...340/258 B X ELECTRIC CIRCUITRY TH2,128,461 8 1938 Jo nson ..240/4l.6 X

2,286,448 6/1942 Wahlberg... .....240/4l.6 X

[72] Inventors: Charles Litman, 4438 Narvaez Crescent; 2,890,351 6/1959Tongret ..250/239 Earl N. Lehna, 320 Bessborough Avenue, 2,918,58512/1959 Farmer ..250/239 both of Victoria, British Columbia, 3,390,3886/ 1968 Kahl et al. ..340/25 8 B Canada Primary ExaminerDavid L. Trafton[22] Flled' 1969 Attorney-Fetherstonhaugh & Co. [2]] Appl. N0.: 886,176

[57] ABSTRACT [30] Foreign Application Priority Data Apparatus having abase attachable to a surface. A hollow A r l 4 1969 Canada 048 571holderis universally supported by the base and an electric elep ment ofa light beam transmitting and receiving circuit is mounted in theholder. The light beam travels through an [52] US. Cl ..340/258 B,240/4165305295 outer end p g of the holder and fined to the holder to 5l 1 Int Cl Gosh 13/18 tend across the outer end opening are a lightfocusing lens and 58] Fieid 258 B 276 a light filter. A rheostat isprovided in the circuit to adjust the intensity of the light beam. Theapparatus has an alarm circuit 178/701 250/239 240/416 which isenergized when the light beam is broken by an object 56] ReferencesCited of a predetermined size and the alarm circuit includes an audibleand a visual signalling device as well as a two-way switch NITED ST TESPAT 5 for selectively and alternatively controlling the two devices. U AEN 243,780 7/1981 Jennings ..240/4L6 X 4 Claims, 4 Drawing Figures 7 3o74 5! i 62 93 k 63 %86 9/ 65 96 76 8 PATEminmzs m2 3,653,021

SHEET 2 0F 2 INVENTORS CHARLES LITMAN EARL N. LEHNA 1 AT TO RNEYSUNIVERSALLY ADJUSTABLE AND FOCUSABLE ALARM APPARATUS AND ELECTRICCIRCUITRY THEREFOR BACKGROUND OF THE INVENTION This invention relates toburgular and fire alarm apparatus of the type which utilizes a beam oflight to guard selected areas of a room or the like.

Conventional alarm systems using an electric eye as a triggering elementare often bulky and expensive with the result that generally they arelimited to use in specific locations in offices and warehouses etc. ofthe more well to do business establishments. The cost factor has beenknown to rule out attempts to adapt such systems for use in smallbusinesses and in private homes since the equipment now on the market isquite complex and remains costly even though simplified and reduced insize. In addition, such alarm sounding equipment must be given certainsafeguards to avoid false alarms and this tends to make them lessreliable. Another reason for loss of effectiveness in alarm systems notspecifically designed for a particular installation, is that the lightbeams cannot be precisely controlled with the result that a small objectsuch as a flying insect or the like can interupt the overly sensitivebeam. This causes frequent false alarms which always annoy and sometimesfrighten a householder and this, of course, is entirely unsatisfactory.

SUMMARY OF THE INVENTION The above as well as other disadvantages ofconventional alarm systems are overcome by the present apparatus whichis small, compact and precision built. Means is provided for mountingthe light beam transmitting and receiving elements so that theseelements can be located near the remainder of the unit as is desirable.Mirrors strategically located about the guarded area reflect the beamalong selected paths between the transmitting and receiving elements. Itthen becomes possible, in some installations at least, to hide theentire unit from view. The two key elements of the apparatus arecontained within housings which permit the light beam to be projected ina variety of directions as might be required for different room layoutsand the beam can be focused by means of a reflector and a lens so thatthere is no unnecessary defusion of the light rays. Filters are providedto render both the light beam, and the photocell receiving the lightbeam, invisible so that an intruder is not forewarned of the presence ofthe alarm and therefore is not able to avoid triggering the system.

These as well as other features and advantages of the present alarmapparatus will be described in detail in the following specification andshown in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS DESCRIPTION OF THE PREFERREDEMBODIMENTS Referring to FIG. 1, there is illustrated a typicalinstallation for the present alarm apparatus, which apparatus isindicated generally by the numeral 10. In this particular installation,the apparatus is shown installed in a room 11 having walls 14, 15, 16and 17. Walls 15 and 16 may have windows 19 and 20 while wall 17 mayhave a door opening 21. The apparatus includes a control unit 24 whichconveniently is fastened to the wall 14, this control unit beingprovided with a number of electrical and electronic circuits one ofwhich is a light beam transmitting and receiving circuit generallyindicated at 25. Circuit 25 includes a main control switch 27, arheostat 28, a transmitter and a receiver 31 as well as numerous otherelements which have not been shown. The transmitter 30 and receiver 31of the apparatus are also fastened to wall 14 preferably adjacent walls15 and 17. This particular installation requires the use of mirrors 33and 34 which are mounted at opposite comers-of the room. A light beam,as indicated by chain dotted line 36 in FIG. 1, is generated by theapparatus and is projected by the transmitter 30 to the mirror 33,thence to mirror 34 and from the latter mirror back to the receiver 31.Apparatus 10 also includes an alarm circuit generally indicated at 40,FIG. 1. This alarm circuit is provided with appropriate elementsincluding a bell 42, a light bulb 43 and a two-way switch 44. Thearrangement is such that whenever the light beam 36 is interrupted, asit would be by an intruder entering the room 11, the circuit 40 isenergized and the bell 42 sounds an alarm to warn others of thebreak-in.

Referring now to FIG. 2, the transmitter generally indicated at 30 isshown to comprise a housing 50 which is provided with a socket-like base51. Base 51 has a peripheral wall 52 and the outer edge 53 of this wallcurves inwardly. A flange 55 is formed on the inner edge of theperipheral wall 52 and preferably this flange is fitted with a disc 56which serves as a closure for the inner end of the base. As shown inFIG. 3, openings 58 are provided in the flange 55 and the disc 56 toreceive screws 59 which are used to secure the transmitter housing 50 tothe wall 14.

Base 51 supports a hollow holder 62 which is a ball-like member having asubstantially spherical sidewall 63 partially enclosed by the peripheralwall 52 of the base. Between the holder wall 63 and the base wall 52, aresilient bearing ring 65 is mounted, the bearing ring being tapered incross section to conform to the adjoining walls of the base 51 andholder 62. A clamping band 67 serves to hold the bearing ring 65 inposition, and this clamping band has a flange 68 which slidably engagesthe peripheral wall 52 of the base. Circumferentially spaced screws 70are fitted to the flange 68, these screws extending through slots 71(FIG. 2 only) formed in the peripheral wall 52 near the flange 55. Thisarrangement enables the clamping band 67 to be moved towards or awayfrom the closure disc 56 as required so as to apply a suitable amount ofcompression to the bearing ring 65 and hold said ring in firm engagementwith the sidewall 63. Thus, the holder 62 is rockingly mounted in thebase 51 and is journalled therein by the bearing ring 65. Thetransmission housing 62 then is similar to a ball and socket joint or,in other words, the holder 62 is supported by the base 51 for limitedfree swinging movement in any direction. The bearing ring 65 journalsthe holder 62 but, at the same time, offers some resistance to swingingmovement due to the compression applied to said bearing ring by theclamping band 67. Since the band 67 is adjustable, the bearing ringcompression can be varied and increased if required to compensate forwear of the resilient bearing material or the sliding parts of thehousing 50. A set screw 74 is fitted to the outer edge 53 of the case soas to engage the sidewall 63 of the holder, this arrangement enablingthe holder 62 to be secured in any selected position to which it may beturned within the base 51.

The inner end 76 of the substantially spherical holder is cut off sothat it is open and is spaced a short distance from the closure disc 56.At the opposite or outer end, the sidewall 63 curves inwardly towards anouter cylindrical neck 78 which provides the holder with an outer endopening 79. The inner surface of the sidewall 53 is fitted with abracket 80 and secured to this bracket is an inwardly dished reflector81. Bracket 80 supports reflector 81 so that the latter member extendsacross the center of the holder 62 near to the inner end 76 and to theopening 79. Reflector 81 is fitted with a centrally disposed socket 83and fitted to this socket is an incandescent lamp 84. The lamp 84 iselectrically connected by a wire 85 into the circuit 25, the wireextending through a grommet 86 mounted on the wall 52 near the flange55.

The neck 78 is provided with a fine thread 90 and mounted on thisthreaded portion of the holder 62 is a sleeve 91 in which a lens 92 issuitably mounted. Lens 92 is a positive or converging lens which issupported by the sleeve 91 to extend across the outer end opening 78 inalignment with the lamp 84. A set screw 93 is fitted to the sleeve 91whereby to engage the neck 78 and lock said sleeve against rotation. Thesleeve 91 has a reduced outer end 94 which is threaded as at 95 toreceive an annular cap 96. Supported between the cap 96 and the outerend of the sleeve 91 so as to extend across and form a second endclosure for the outer end opening 79, is an infrared light filter 98.

The receiver generally indicated at 31 is shown in FIG. 4 to be ofsubstantially the same construction as the transmitter 30 and, forconvenience, the'corresponding parts of said receiver are designated bythe same reference numeral and the identifying letter A. The bracket 80Aof the holder 62A supports a transverse arm 100 and mounted on this armis a photoelectric cell 101. The photocell or, as it is commonly called,electric eye 101 is positioned in the center of the housing 50A inalignment with the positive lens 92A and infra-red filter 98A of thereceiver 31. A wire 103 connects and photocell 101 into the circuit 25.I

When the apparatus has been secured to the wall 14 as previouslydescribed, circuit 25 is plugged into a wall outlet for other source ofpower, not shown, and the switch 27 is closed. Switch 44 is moved to thedotted line position of FIG. 1 to connect the lamp 43 into the circuit40 and the unit 24 then is ready to be adjusted so as to guard the room11 against intruders. This adjustment is done with the caps 96 andfilters 98 removed from both the transmitter 30 and receiver 31. First asuitable line is selected for the light beam 36 to travel from the pointof projection through the mirrors 33 and 34 and back to the receiver 31.Both mirrors of course are adjustably mounted so that they can be raisedor lowered as required and turned to any desired angle with respect tothe walls and 16. The holder 62 is swung about the base 51 and themirrors 33 and 34 are turned so the beam 36 being projected from thetransmitter cuts across the windows 19 and and door 21 at an appropriatelevel before being returned to the receiver 31. By moving the holder 62Aabout in the base 51A, the receiver is properly aligned so that the beam36 enters the opening 79A and strikes the photocell 101. Sleeve 91 isadjusted to focus the lens 92 as required and similarly the lens 92A isadjusted by a movement of the sleeve 91A so that the beam 36 fallsdirectly on the electrode of the photocell 101. Once the finaladjustments to the several parts have been made and the desired focusinghas been achieved, the set screws 74 and 74A as well as 93 and 93A aretightened to lock the parts in their set positions.

The apparatus is now ready to be tested, and this can be done by passingan object through the beam 36 so as to complete the circuit 40 and lightthe lamp 43. This lighting of lamp 43 signifies the apparatus is inproper working order and at this stage, the rheostat 28 can be adjustedto reduce the out: put of the transmitter 30 to a desired low level. Thelight intensity of the beam 36 is reduced so that it is sufficientlysensitive to detect smoke but at the same time care is taken not toreduce it to a point where a flying insect or a piece of blown paperwill set off the alarm. Once it is determined the apparatus isoperational, the switch 44 is moved to the solid line position of FIG. 1whereupon the lamp 43 is cut out of the circuit 40 and the bell 42 isplaced therein. The two infra-red filters 98 and 98A are then fitted tothe transmitter and receiver by replacement of the caps 96 and 96A. Thefilter 98 serves to remove the visable rays of light from the beam 36and the filter 98A blocks all room light or sun light which mightotherwise reach and influence the photocell 101. Thus, no visualindication is given of the presence of the light beam 36.

As previously mentioned, the alarm bell 42 will ring any time anintruder walks through the door 21 or enters one of the windows 20 or19. The control unit 24 has a holding relay, not shown, which causes thebell 42 to continue to ring once the beam is interrupted and the alarmwill sound until the householder enters the room 11 and reopens thehidden switch 27. Should a fire occur in the room 11', the smoke itproduces will also out the beam 36 and trigger the alarm,

From the foregomg it will be apparent there 15 provided a simple yetextremely effective alarm system which is particularly well suited foruse in the home or in small offices or the like. The degree of controlof the beam provided by the transmitter and receiving housings and theability to precisely focus the light rays ensures that the alarm isalmost foolproof and is completely reliable. By means of the rheostat28, the wattage of the lamp 84 can be reduced from a maximum whichpreferably is 5 watts (24 volts) to a minimum of say, 2 watts therebyeliminating excess heat in the housing 51 so as to extend the operatinglife of the light transmitting bulb 84. At the same time, lightintensity is reduced to a point where the beam 36 is sufficientlysensitive to detect small amounts of smoke so the unit will operateeffectively as a fire alarm. The two precision made lenses of thetransmitter and receiver make it possible to transmit the light beamover a distance in excess of I40 feet with the light beam being renderedinvisable by the use of the infra-red filters. Tests have proven that anobject of onefourth inch in diameter can pass through the light beamwithout setting off the alarm and therefore a small flying insect willnot cause a false alarm. The alarm apparatus can be quickly and easilyinstalled and the light beam can be properly focused in a very shorttime due to the swivel action provided by the projector and receiverhousings.

We claim:

1. Alarm apparatus comprising a base adapted to be attached to asurface, a hollow holder supported by the base for limited free swingingmovement in any direction, a resilient bearing ring interposed betweenthe base and the hollow holder, a clamping plate secured to the base tocompress the resilient bearing ring against the hollow holder, a neckformed on the hollow holder remote from the base and defining an outerend opening, a light beam transmitting and receiving circuit includingan electric element supported within the hollow holder, a sleevethreadedly secured to the neck, a lens carried by the sleeve to extendacross the outer end opening and focus the light beam, a light filtersupported by the sleeve adjacent the lens to filter out visible rays ofthe light beam, and including an alarm circuit adapted to be energizedwhen the light beam is broken; said alarm circuit including an audible'signalling device, a visual signalling device, and a two-way switchoperable to disconnect a selected one of said devices from said alarmcircuit.

2. Alarm apparatus as claimed in claim 1, and including locking meansfor securing the hollow holder in a selected position on the base.

3. Alarm apparatus as claimed in claim 1, and including means forsecuring the sleeve against rotational movement on the neck.

4. Alarm apparatus as claimed in claim 1, in which said light beamtransmitting and receiving circuit includes a rheostat for controllingthe intensity of the light beam.

1. Alarm apparatus comprising a base adapted to be attached to a surface, a hollow holder supported by the base for limited free swinging movement in any direction, a resilient bearing ring interposed between the base and the hollow holder, a clamping plate secured to the base to compress the resilient bearing ring against the holLow holder, a neck formed on the hollow holder remote from the base and defining an outer end opening, a light beam transmitting and receiving circuit including an electric element supported within the hollow holder, a sleeve threadedly secured to the neck, a lens carried by the sleeve to extend across the outer end opening and focus the light beam, a light filter supported by the sleeve adjacent the lens to filter out visible rays of the light beam, and including an alarm circuit adapted to be energized when the light beam is broken; said alarm circuit including an audible signalling device, a visual signalling device, and a two-way switch operable to disconnect a selected one of said devices from said alarm circuit.
 2. Alarm apparatus as claimed in claim 1, and including locking means for securing the hollow holder in a selected position on the base.
 3. Alarm apparatus as claimed in claim 1, and including means for securing the sleeve against rotational movement on the neck.
 4. Alarm apparatus as claimed in claim 1, in which said light beam transmitting and receiving circuit includes a rheostat for controlling the intensity of the light beam. 